Feed mechanism for wrapping machines



E. H. LAZEN BY FEED MECHANISM FOR WRAPPING MACHINES Aug. 29, 19 7 4 Sheets-Sheet 1 Filed March 51, 1964 Aug. 29, 1967 E. H. LAZENBY FEED MECHANISM FOR WRAPPING MACHINES 4 Sheets-Sheet 3 Filed March 31, 1964 Aug. 29, 1967 E. H. LAZENBY 3,338,023

FEED MECHANISM FOR WRAPPING MACHINES Filed March 31, 1964 4 Sheets-Sheet 4 ihad/ 0L 5% WW $3.0m wwww rrda/rys United States Patent 3,338,023 FEED MECHANISM FOR WRAPPING HlNES This invention relates to apparatus for feeding at predetermined intervals to a wrapping machine articles to be wrapped, e.g., meats, which are non-slidable, i.e., which should not be subjected to any sliding action when they are transferred from one supporting surface to another.

Such articles are normally fed to the wrapping machine by a pocketed chain conveyor into which the articles are placed by hand, mechanism being provided for transferring the articles in succession from the chain pockets to a Web of wrapping material. Because of the difiiculties involved in handling non-slidable articles, the transfer mechanism tends to be complicated in construction and expensive to produce. Such forms of infeed mechanism are often limited in speed and application and difiicult to feed efiiciently.

With a view to overcoming these difiiculties, the invention provides an infeed mechanism, for feeding non-slidable articles at predetermined intervals to a wrapping machine, comprising a thin flat conveyor belt marked at regular intervals to define throughout its horizontal top run areas of equal length indicating the pitch at which the operator should place the articles manually on the belt, the belt having a small nose pulley at its delivery end, a support placed close to said nose pulley and means for feeding a web of wrapping material over the support so that it travels horizontally in alignment with the upper run of the belt and at the same speed as the belt. Because of the flexibility of the thin belt the nose pulley can be made quite small so that the unsupported length of the articles as they are transferred to the web is reduced to a minimum.

The infeed mechanism also includes means for reducing belt slip to a minimum and for correcting any slip or creep of the belt which are described more fully below.

One form of infeed mechanism according to the invention will now be further described, by way of example, with reference to the accompanying diagrammatic drawing, in which:

FIG. 1 is a side elevation of the infeed mechanism and an associated entubing mechanism,

FIG. 2 is a section on the line II-II in FIG. 1,

FIG. 3 is a corresponding plan view,

FIG. 4 is a side elevation showing the infeed mechanismv associated with a different form of entubing mechanism and FIG. 5 is a corresponding plan View. v

The infeed mechanism shown in FIGS. 1-3 includes a thin flat belt 1, approximately 1 mm. thick, located by guide pulleys 9, 12 mounted on a suitable framework (not shown) and driven by a large diameter drum 2. The nose pulley 3 of the belt conveyor 1 is positioned close to a roller 4 over which a web 5 of wrapping material is being fed by the entu-bing mechanism of the wrapping machine. The drum 2 is driven from the wrapping machine and drives the belt 1 at a linear speed equal to the linear speed of the web 5 of wrapping material.

In the construction shown in FIGS. 1-3 the entubing mechanism forms a tube from the web 5 and another web 15, the two webs being drawn over a tube former 13 and sealed together, by heated sealing rollers 14, along their contacting edges as indicated at 16 in FIG. 3. The two webs are fed through the entubing mechanism by a pair of feed rollers 17, which may be driven continuously from the main drive shaft 18 of the wrapping machine by a chain drive 19, as indicated in FIG. 1. Alternatively, the feed rollers 17 may be driven intermittently. Transverse seals 20 (FIG. 3) are formed in the tube between successive articles 7 by heated crimping rollers 21, which are driven from the shaft 18 by a chain drive 22.

Alternatively, as shown in FIGS. 4 and 5, the tube may be formed from the web 5 only, which is fed over a tube former 23 by heated rollers 24 which also serve to form a sealed overlap joint 25 at the top of the tube.

The face of the belt 2 is marked off by lines 8 into a number of equal pitches 6, and these pitch lengths are the same as the length of wrapping material required for the individual articles 7. The lines 8 are indelible and are of a contrasting colour to the belt and they indicate where the operator should place the articles when feeding as indicated in FIG. 3. Side guides 11 (FIGS. 23) are provided along the top run of the belt.

Because of the flexibility of the thin 'belt 1 it is possible to make the nose pulley 3 quite small in diameter, e.g., /z-% inch, with the result that the gap X over which the articles travel unsupported is cut down to a minimum and effective transfer of the articles from the belt 2 to the Web 5 is not seriously impaired at this point.

If a positive type of conveying means (i.e., a toothed belt or chain pockets, etc.) had been employed instead of the flat belt a nose pulley of much larger diameter would have been deeded, the length X would have been considerably greater and efiicient transfer would not have been possible.

In order to ensure that the belt maintains correct synchronisation with the wrapping machine and consistently feeds the articles forward at the correct speed and pitch on to the wrapping material 5 the following control means are provided:

(a) In order to reduce belt slip or creep to a minimum, the maximum amount of belt surface contact has been provided on the driving drum 2 by guide pulleys 9 located at the top of the drum on opposite sides thereof as shown in FIG. 1.

(b) A photoelectric cell 10 mounted above the belt 1 is synchronise-d with the wrapping machine to scan the lines 8 on the belt. The cell 10 detects electronically errors in registration (above predetermined limits) of the lines 8 with the web 5 arising from belt slip or creep. When an error is detected a control mechanism is activated to effect a slight increase or decrease in the speed of the driving drum 2 until the error is rectified and the belt 1 is returned to correct register.

This control mechanism operates as follows:

The drum 2 is driven by a chain drive 26 from a shaft 27 which, in turn, is driven from the driving shaft 18 of the wrapping machine through a chain drive 28 and gearing 29. The shaft 27 (FIG. 2) carries a sun wheel 30 which meshes with pinions 31 on a normally stationary carrier 32. Other pinions 33 on the carrier 32 mesh with a gear 34 attached to a sprocket 35 which drives the chain 26 driving the drum 2.

When the photoelectric cell 10 detects a line 8 on the belt 1 it sends a signal to an amplifier 36. So long as the lines 8 remain in correct register with the web 5, these signals are applied to the amplifier 36 simultaneously with signals from a timer 37, and the amplifier remains inactive. In the event of an error in registration, the signals from the cell 10 will be applied to the amplifier 36 before or after the signals from the timer 37, and the amplifier responds by energising a relay 38, which causes a servo motor 39 to rotate in the appropriate direction, so rotating the carrier 32 through a chain drive 40 to slow down or increase the speed of the drum 2 until the error has been rectified. 7

What I claim as my invention and desire to secure by Letters Patent is:

1. Apparatus for wrapping non-slidable articles, comprising a thin substantially smooth-surfaced conveyor belt uninterrupted by protuberances for feeding said articles forward at uniform spacing, said belt having a horizontal top run and a bottom run, said belt being marked at regular intervals to define throughout its horizontal top run areas of equal length indicating the pitch at which the operator should place the articles manually on the belt, a small nose pulley at the delivery end of said belt, a support having a receiving end placed close to said nose pulley, means for feeding a web of wrapping material from below over the support and through the narrow space between the said end of the support and the nose pulley so that said web travels horizontally in alignment with the top run of the belt and at the same speed as the belt, thereby permitting of transfer without sliding of said articles from the moving belt directly to the moving web, an entubing mechanism arranged to fold said web upwardly around said articles as they are carried on said web through the entubing mechanism, a drum of large diameter arranged to be substantially enveloped by and to drive the bottom run of said belt, guide pulleys for the belt adjacent the top of said bottom run which constrain the belt to embrace the major portion of said drum, a photo-electric cell for scanning the marks on the belt and means controlled by said cell for adjusting the speed of the drum to correct errors in registration of the marks arising from slip of creep of the belt, to insure substantially equal speed of the belt and of the web feeding means.

2. Apparatus as claimed in claim 1, wherein said entubing mechanism is arranged to form said web into a tube surrounding said articles and having a longitudinal top joint.

3. Apparatus as claimed in claim 1, which includes means for feeding a second web of wrapping material from above to said entubing mechanism and wherein said entubing mechanism includes means for joining the webs together at their edges to form a tube surrounding said articles.

References Cited UNITED STATES PATENTS 2,309,621 2/1943 Allatt 53-'33 2,375,451 5/ 1945 Waters 271-2.3' 2,597,042 5/1952 Stokes et al 53180 2,808,922 10/1957 Lutman 19882 3,007,295 11/1961 Heinzer 53-180 3,155,221 11/1964 Griner 198 4 FOREIGN PATENTS 829,313 3/1960 Great Britain. 887,470 1/ 1962 Great Britain.

TRAVIS S. MCGEHEE, Primary Examiner.

N. ABRAMS. Assistant Examiner. 

1. APPARATUS FOR WRAPPING NON-SLIDABLY ARTICLES, COMPRISING A THIN SUBSTANTIALLY SMOOTH-SURFACED CONVEYOR BELT UNINTERRUPTED BY PROTUBERANCES FOR FEEDING SAID ARTICLES FORWARD AT UNIFORM SPACING, SAID BELT BEING MARKED AT REGULAR TOP RUN AND A BOTTOM RUN, SAID BELT BEING MARKED AT REGULAR INTERVALS TO DEFINE THROUGHOUT ITS HORIZONTAL TOP RUN AREAS OF EQUAL LENGTH INDICATING THE PITCH AT WHICH THE OPERATOR SHOULD PLACE THE ARTICLES MANUALLY ON THE BELT, A SMALL NOSE PULLEY AT THE DELIVERY END OF SAID BELT, A SUPPORT HAVING A RECEIVING END PLACED CLOSE TO SAID NOSE PULLEY, MEANS FOR FEEDING A WEB OF WRAPPING MATERIAL FROM BELOW OVER THE SUPPORT AND THROUGH THE NARROW SPACE BETWEEN THE SAID END OF THE SUPPORT AND THE NOSE PULLEY SO THAT SAID WEB TRAVELS HORIZONTALLY IN ALIGNMENT WITH THE TOP RUN OF THE BELT AND AT THE SAME SPEED AS THE BELT, THEREBY PERMITTING OF TRANSFER WITHOUT SLIDING OF SAID ARTICLES FROM THE MOVING BELT DIRECTLY TO THE MOVING WEB, AN ENTUBING MECHANISM ARRANGED TO FOLD SAID WEB UPWARDLY AROUND SAID ARTICLES AS THEY ARE CARRIED ON SAID WEB THROUGH THE 